Ron van Daal discovered that phpBB contains a vulnerability in the highlighting code.

Impact

Successful exploitation would grant an attacker unrestricted access to the PHP exec() or system() functions, allowing the execution of arbitrary commands with the rights of the web server.

Workaround

Please follow the instructions given in the phpBB announcement.

Resolution

The phpBB package is no longer supported by Gentoo Linux and has been masked in the Portage repository, no further announcements will be issued regarding phpBB updates. Users who wish to continue using phpBB are advised to monitor and refer to www.phpbb.com for more information. To continue using the Gentoo-provided phpBB package, please refer to the Portage documentation on unmasking packages and upgrade to 2.0.16.